In this paper the quantum cosmological consequences of introducing a term cubic in the Ricci curvature scalar R into the Einstein--Hilbert action are investigated. It is argued that this term represents a more generic perturbation to the action than the quadratic correction usually considered. A qualitative argument suggests that there exists a region of parameter space in which neither the tunnelling nor the no-boundary boundary conditions predict an epoch of inflation that can solve the horizon and flatness problems of the standard big bang model. This is in contrast to the -theory.